This invention relates to a method for managing a channel state in an extended region base station in a mobile communication system; and more particularly, to a method for managing a channel state in an extended region base station in a mobile communication system, wherein at least two channel states are reported from each of at least two channel elements.
Generally, in a code division multiple access (CDMA) mobile communication system including a mobile station (MS), a base transceiver station (BTS), a base station controller (BSC) and a mobile switching center (MSC), a traffic region is restricted within a cell radius of 60 km due to a technical limitation of a cell site modem (CSM) ASIC (application specification integrated circuit). Also, depending on capacity of a mobile communication system, a cell radius of approximately 7 km is enough for the traffic region to provide a communication service in the center of a city.
However, in case a service needs to be provided in a coastal area or an island area where the BTS is hard to install or a country area where a service area is too broad and a subscriber density is low, there is caused a problem that it is not avoidable to install unnecessary BTSs.
To extend the traffic region in the conventional way, a pair of CSM ASICs including two CSM ASICs should be used. In this case, one CSM ASIC is used for covering a normal region meaning a region within a cell radius of 60 km and the other ASIC is used for an extended region meaning a region within a cell radius of 60 km to 120 km. Simple adjustment of hardware and control of software are needed to perform the traffic region extension without redesigning the CSM ASIC.
As described above, overall traffic region can be extended by including a plurality of normal regions and extended regions that are covered by corresponding pair of the CSM ASICs. When the MS moves from the normal region to the extended region and vice versa, there is needed a handoff region where all of two CSM ASICs can perform a phase tracking of a reverse channel signal in order to perform good call processing between the regions without traffic disconnection.
In a conventional BTS for a single traffic region, one forward/reverse traffic channel is assigned to one CSM. In this case, a way of managing a channel state in the BTS for the single traffic region is as follows.
Each channel element corresponding to each of a plurality of CSMs classifies a state of the channel element into an abnormal state, a loading state, an idle state and a busy state, and reports a current state of itself to a state management block (SMB) of a BTS control processor (BCP) that is a higher-leveled control processor of the channel element.
Then, the BCP reports the current state of the channel element to a call control processor (CCP) of the BSC that is a higher-leveled control processor of the BCP.
In the above four states of the channel element, the abnormal state represents a state where the channel element is not operated normally; the loading state represents an initialization state of the channel element; the idle state represents a state where an normal initialization is performed and then the channel element stands by for a call assignment; and the busy state represents a traffic state.
The SMB of the BCP/CCP manages the reported state of the channel element and provides database that is needed to be used at a call processing block (CPB), a statistics processing block (SPB) and a resource allocation block (RAB).
However, in a BTS for an extended traffic region where the traffic region is divided into the normal region, the handoff region and the extended region, the call processing should be performed under an assumption that a pair of fixed physical channels is a logical channel.
The conventional way for managing the channel state by which one CSM is used for the call processing in the BTS for the single traffic region, causes lots of problems such as traffic disconnection in providing an extended traffic region service to thereby be unable to operate the BTS for the extended traffic region.
It is an object of the present invention to provide a method for managing states of a pair of channel elements including a normal channel element for a normal traffic region and an extended channel element for an extended traffic region in an extended traffic region base station that includes a state management block (SMB), a call processing block (CPB), a resource allocation block (RAB), a statistics processing block (SPB) and a base station manager (BSM) in order to enable operate the extended traffic region base station.
In accordance with an aspect of the present invention, there is provided a method for managing states of a pair of channel elements including a normal channel element for a normal traffic region and an extended channel element for an extended traffic region in an extended traffic region base station that includes a state management block (SMB), a call processing block (CPB), a resource allocation block (RAB), a statistics processing block (SPB) and a base station manager (BSM), including the steps of: by each of the normal channel element and the extended channel element, reporting current states of each of the normal channel element and the extended channel element to the SMB, wherein the current state is one of an abnormal state, a loading state, an idle state and a busy state; by the SMB, combining the current states to thereby generate a combined state; and by the SMB, reporting the combined state to a set of the CPB and the RAB and a set of the SPB and the BSM.